LLM Post-Training Engineer Intern: Multimodal AI

TikTok; San Jose (CA); On-site; USD 52,000 - 72,000; Part time

Benefits offered by this job

Health insurance (day one)

Life insurance

Wellbeing benefits

10 paid holidays per year

Paid sick time

Housing allowance (non-remote)

Job summary

TikTok invites students to join its Multimedia AI team for a campus internship focused on post-training methods, evaluation pipelines, and bridging research with production AI applications across video understanding and content classification.

You will collaborate with engineers on instruction tuning, RLHF, and multimodal experiments while gaining hands-on experience, industry exposure, and opportunities through development workshops and social programs.

Qualifications

• Currently pursuing an Undergraduate or Master’s degree in Computer Science, Machine Learning, or a related technical discipline.
• Strong programming skills in Python and experience with deep learning frameworks such as PyTorch or JAX.
• Foundational understanding of Transformer architectures and LLM training principles.
• Demonstrated ability to learn quickly in a fast-paced environment and a strong passion for AI "landing" and product application.

Responsibilities

• Support the development and optimization of post-training strategies, including instruction tuning, preference tuning (SFT/DPO/PPO), and model alignment.
• Assist in building robust evaluation pipelines to measure model performance, helpfulness, and safety across diverse multimedia product use cases.
• Participate in the research and implementation of cutting-edge methodologies in reward modeling and human preference learning.
• Collaborate with engineering teams to bridge the gap between experimental research and production-ready AI applications (e.g., video understanding, translation, and content classification).
• Analyze and process large-scale datasets to identify patterns that improve model behavior and alignment quality.

Skills

Python

PyTorch

JAX

Transformer

LLM training

LLM fine-tuning

RLHF

DeepSpeed

Megatron-LM

Multimodal AI

Education

Pursuing Undergraduate or Master’s in Computer Science, Machine Learning, or related technical discipline

Tools

DeepSpeed

Megatron-LM

Job description

TikTok invites students to join its Multimedia AI team for a campus internship focused on post-training methods, evaluation pipelines, and bridging research with production AI applications across video understanding and content classification.

You will collaborate with engineers on instruction tuning, RLHF, and multimodal experiments while gaining hands-on experience, industry exposure, and opportunities through development workshops and social programs.